An integrated circuit is a semiconductor device that includes many electronic components (e.g., transistors, diodes, inverters, etc.). These electrical components are interconnected to form larger scale circuit components (e.g., gates, cells, memory units, arithmetic units, controllers, decoders, etc.) on the integrated circuit. The electronic and circuit components of integrated circuits are jointly referred to below as “components.” An integrated circuit also includes multiple layers of metal and/or polysilicon wiring that interconnect its electronic and circuit components.
For an integrated circuit to operate properly, all of the electronic and circuit components must operate in a synchronized manner. A ‘clock signal’ is used to synchronize the electronic and circuit components. A clock signal is generally an oscillating signal that is used by the various circuit components like a coxswain that keeps rowers in a racing shell synchronized.
To keep circuits on an integrated circuit synchronized, a clock signal must be distributed to the circuits on the integrated circuit with very little skew. However, if two different circuits are coupled to the same clock source with clock distribution lines having very different lengths, the different length clock lines will inherently cause clock skew.
To prevent such clock skew, most integrated circuits implement a special clock distribution network. The clock distribution network distributes the clock signal to a set of different areas with an equidistant clock signal lines. Each destination area is generally small enough such that differences between clock line lengths within the clock area are insignificant.
Many integrated circuits are currently fabricated with five metal layers for interconnecting circuit modules. Generally, each metal layer has a preferred wiring direction in an attempt to maximize the number of signal wires that may be placed on each wiring layer by preventing intersections. In current integrated circuits, the preferred direction alternates between successive metal layers.
Most integrated circuits use a “Manhattan” wiring model, which specifies alternating layers of horizontal and vertical preferred-direction wiring. (Viewed from above, the horizontal and vertical interconnect wires of the integrated circuit resemble the orthogonal streets of Manhattan.) In the Manhattan wiring model, essentially all of the interconnect wires are horizontal or vertical. However, new wiring systems have been introduced that allow diagonal (non Manhattan) interconnect wiring. Diagonal wiring allows different circuits that are separated by a diagonal distance to be coupled with a shorter diagonal wire instead of using a longer combination of vertical and horizontal wires.
In addition to connecting integrated circuit components, non Manhattan wiring can be used to distribute clock signals. Thus, a new set of clock signal wiring structures that have been designed with the premise of non Manhattan wiring would be desirable for maximizing the efficiencies of non Manhattan wiring.